Selected Methods in Angular Rotor Speed Estimation for Induction Motor Drives

This paper presents selected methods in angular rotor speed estimation for induction motor drives. Modern control schemes for high-performance drives (e.g. Field Oriented Control, Direct Torque Control) are based on precise knowledge of some physical quantities that are hard to measure or are immeasurable in standard machine (e.g. fluxes). Other quantities needed for control require additional transducers that are expensive in comparison to overall costs of the drive or can decrease reliability when operated in hostile environment (e.g speed encoders). Thus, many researchers focus on developing various estimation algorithms to enable construction of low-cost high-performance reliable drives. The favoured estimation model type depends very much on the researcher and the process to be controlled and hence this paper does not attempt to make a value judgement as to which is best. Nevertheless, we will try to take a critical look at some aspects of selected artiflcial-neural-networks-based solutions.